Question

разложите на множетели xy^4-2y^4-xy+2y
9-x^2-2xy-y^2

Answer 1

xy(y^3 - 1) -2y(y^3-1) = (xy - 2y)(y^3-1)=y(x-2)(y^3-1)

9-(x^2+2xy+y^2) = 9-(x+y)^2 = (3-x-y)(3+x+y)